1. Field of the Invention
This invention is a further development in the high-power microwave art, and in particular provides a ferrite-to-metal bond that will tolerate standing-wave conditions in a microwave circulator for an extended length of time.
2. Description of the Prior Art
One method for achieving non-reciprocal transmission of power in a microwave system is by means of a circulator having a pair of symmetrically disposed gyromagnetic ferrite or garnet buttons mounted therein to concentrate the flux lines of an externally produced magnetic field. Interaction of the microwave with the externally magnetized gyromagnetic ferrite or garnet buttons will cause transmission of the microwave power only in a particular direction. Prior to the present invention, such ferrite or garnet buttons had been bonded to opposing metal walls of a circulator by a dielectric bonding material such as an epoxy or a mixture of epoxies. It has been found, however, that for high-power levels that are frequently encountered in microwave systems, dielectric bonding material is likely to melt, evaporate, bubble or boil out thereby causing the bond to fail. Until the present invention, a metallizing technique had not been developed which could provide a bond capable of withstanding high-power levels such as would occur under standing wave conditions caused by a frequency mismatch between, for example, a resonant linear accelerator load and a magnetron power source.